U.S. patent application number 15/134012 was filed with the patent office on 2017-10-26 for spectrum admission control.
The applicant listed for this patent is AT&T Intellectual Property I, L.P., AT&T Mobility II LLC. Invention is credited to Arthur R. Brisebois, Zhi Cui, Giuseppe De Rosa.
Application Number | 20170311277 15/134012 |
Document ID | / |
Family ID | 60090511 |
Filed Date | 2017-10-26 |
United States Patent
Application |
20170311277 |
Kind Code |
A1 |
De Rosa; Giuseppe ; et
al. |
October 26, 2017 |
SPECTRUM ADMISSION CONTROL
Abstract
A primary user of a spectrum, such as a licensed user, has
primary access authority to use of a spectrum. A plurality of
secondary users of the spectrum, which may be unlicensed users,
have secondary access authority to use of the spectrum. When the
primary user wants to use the spectrum, the primary user sends a
message that is propagated to all the secondary users in a
geographic region that the primary user wants to use the spectrum.
The message specifies the duration of time and the geographic
region (location of use) where the primary user wants to use the
spectrum. The secondary users in the location of use immediately
stop using the spectrum for the duration of time specified in the
message and then may resume use of the spectrum.
Inventors: |
De Rosa; Giuseppe; (Atlanta,
GA) ; Brisebois; Arthur R.; (Cumming, GA) ;
Cui; Zhi; (Sugar Hill, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AT&T Intellectual Property I, L.P.
AT&T Mobility II LLC |
Atlanta
Atlanta |
GA
GA |
US
US |
|
|
Family ID: |
60090511 |
Appl. No.: |
15/134012 |
Filed: |
April 20, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 48/18 20130101;
H04W 48/10 20130101; H04W 16/14 20130101; H04W 60/04 20130101 |
International
Class: |
H04W 60/04 20090101
H04W060/04; H04W 48/18 20090101 H04W048/18; H04W 16/14 20090101
H04W016/14 |
Claims
1. A method comprising: sending a message from a primary user node,
having a first access authority to use of a spectrum, to one or
more secondary user nodes of the spectrum, the secondary user nodes
having a second access authority to use of the spectrum that is
lower than the first access authority, the message indicating that
the primary user node wants use of the spectrum, and wherein the
message specifies a duration of use by the primary user node.
2. The method as recited in claim 1 further comprising: sending the
message from the primary user node to one of the secondary user
nodes; and sending information in the message from the one of the
secondary user nodes to one or more additional secondary user
nodes.
3. The method as recited in claim 2 further comprising: sending the
message from the primary user node to the one of the secondary user
nodes over a wireline communication link or a wireless
communication link.
4. The method as recited in claim 1 wherein the one of the
secondary user nodes is a closest node to the primary user
node.
5. The method as recited in claim 1 wherein the primary user node
is a licensed user.
6. The method as recited in claim 1 further comprising: sending a
second message from one of the secondary user nodes to one or more
tertiary user nodes, the one or more tertiary user nodes having
lower access authority to use of the spectrum than the one of the
secondary user nodes, the second message indicating that the one of
the secondary user nodes wants use of the spectrum.
7. The method as recited in claim 6 wherein the second message
specifies a second duration of use by the one of the secondary user
nodes after which the one or more tertiary user nodes can again use
the spectrum.
8. The method as recited in claim 1 wherein the primary user node
is a radar and the spectrum is used by the radar.
9. The method as recited in claim 1 wherein the secondary user
nodes are part of a wireless cellular communication system and the
primary user node uses the spectrum for other than wireless
cellular communications.
10. An apparatus comprising: a secondary user node configured to
receive a message from a primary user node of a spectrum having a
higher access authority to the spectrum than the secondary user
node, the message indicating that the primary user node wants use
of the spectrum and wherein the message specifies a duration of use
by the primary user node; and wherein the secondary user node is
responsive to the message to avoid use of the spectrum during the
duration of use by the primary user node.
11. The apparatus as recited in claim 10 wherein the secondary user
node is further configured to disseminate the message to one or
more other secondary user nodes of the spectrum having a lower
access authority than the primary user node.
12. The apparatus as recited in claim 10 further comprising:
wherein the secondary user node is configured to receive the
message over a wireline communication link.
13. The apparatus as recited in claim 10 wherein the secondary user
node is a base station.
14. The apparatus as recited in claim 10 wherein the primary user
node is a licensed user of the spectrum.
15. The apparatus as recited in claim 10 wherein the secondary user
node is further configured to send a second message to one or more
tertiary user nodes, the one or more tertiary user nodess having a
lower access authority to the spectrum than the secondary user
node, the second message indicating that the secondary user node
wants use of the spectrum.
16. The apparatus as recited in claim 15 wherein the second message
specifies a second duration of use of the spectrum.
17. The apparatus as recited in claim 10 wherein the primary user
node is a radar system.
18. The apparatus as recited in claim 10 wherein the secondary user
node is part of a a wireless cellular communication system and the
primary user node uses the spectrum for other than wireless
cellular communications.
19. A system comprising: a primary user having a first access
authority to use of a spectrum; a plurality of secondary users of
the spectrum having a second access authority to use of the
spectrum, the second access authority being lower than the first
access authority; and wherein the primary user is configured to
send a message to at least one of the secondary users indicating
that the secondary users should stop using the spectrum for a
specified duration in a specified geographic location.
20. The system as recited in claim 19 wherein one of the secondary
users is configured to forward the message to one or more others of
the secondary users.
21. The method as recited in claim 1 wherein one or more of the one
or more secondary users resumes use of the spectrum responsive to
an end of a time period specified by the duration of use.
22. The apparatus as recited in claim 10 wherein the secondary user
is responsive to an end of a time period specified by the duration
of use to resume use of the spectrum.
Description
BACKGROUND
Field of the Disclosure
[0001] This disclosure relates to sharing spectrum between primary
and secondary users of a spectrum band.
Description of the Related Art
[0002] Geo-location database (DB) systems are currently being
considered for database assisted spectrum assignment in shared
mode. The geo-location database keeps various information on
spectrum license assignees users (primary users) and possibly non
spectrum license assignees users (secondary users). For example, TV
White Space (TVWS) are frequencies available for unlicensed use at
locations where the frequencies are not currently used by the TV
broadcaster (the primary user in this example). TV broadcast may
also be limited to particular times or locations. Thus, a TVWS
database stores TV tower locations, antenna heights, user types,
device transmitter power, technology, operation channel(s),
duration of use, and other relevant information. In a
database-based spectrum access scheme, secondary users first query
the database about the available shared frequencies in their
geo-location in terms of latitude and longitude, and in return
receive the list of unoccupied shared frequencies before initiating
a communication. That approach may be sufficient in static
conditions where the primary user is statically utilizing shared
spectrum in a defined and limited location/region. However, the
database lookup scheme may result in inefficient use of shared
spectrum where more dynamic use of shared spectrum is
desirable.
SUMMARY OF EMBODIMENTS
[0003] A dynamic spectrum access approach, where at least some of
the users, primary and/or secondary, are mobile and discontinuously
active, should provide dynamic information relative to spectrum
availability in space and time.
[0004] Accordingly, in one embodiment a method is provided that
includes sending a message from a primary user node, having a first
access authority to use of a spectrum, to one or more secondary
user nodes of the spectrum having a second access authority to use
of the spectrum that is lower than the first access authority, and
wherein the message specifies a duration of use by the primary
user.
[0005] In another embodiment a secondary user node (e.g., a
wireless operator's base station) is configured to receive a
message from a primary user node of a spectrum having a higher
access authority to the spectrum than the secondary user node. The
message indicates that the primary user node wants use of the
spectrum. The message specifies a duration of use by the primary
user node. The secondary user node is responsive to the message to
avoid use of the spectrum during the duration of use by the primary
user node.
[0006] In another embodiment a system includes a primary user
having a first access authority to use of a spectrum. The system
further includes a plurality of secondary users of the spectrum
having a second access authority to use of the spectrum, the second
access authority being lower than the first access authority. The
primary user is configured to send a message to at least one of the
secondary users indicating that the secondary users should stop
using the spectrum for a specified duration in a specified
geographic location.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present disclosure may be better understood, and its
numerous objects, features, and advantages made apparent to those
skilled in the art by referencing the accompanying drawings.
[0008] FIG. 1 illustrates a high level block diagram of a system
that utilizes an embodiment of the spectrum admission control
mechanism.
[0009] FIG. 2A illustrates an embodiment with three different
access priorities to spectrum.
[0010] FIG. 2B illustrates an example of geographic coverage
associated with the different access priorities
[0011] FIG. 3A shows an embodiment utilizing wireless transmission
of signal-0.
[0012] FIG. 3B shows an embodiment utilizing wired transmission of
signal-0.
[0013] FIG. 3C shows an embodiment utilizing wired and wireless
transmission of signal-0.
[0014] FIG. 4 illustrates a high level flow diagram of a secondary
user deactivating and resuming use of spectrumX.
[0015] FIG. 5 illustrates and example of a base station that may be
utilized in one or more embodiments.
[0016] The use of the same reference symbols in different drawings
indicates similar or identical items.
DETAILED DESCRIPTION
[0017] A shared radio spectrum resource, also referred to herein as
spectrumX, is accessed according to a spectrum admission control
mechanism that provides dynamic access to the spectrum. A primary
user may be a licensed user of the spectrum. The primary user (or
users) have higher access authority for spectrum use than the
secondary users. SpectrumX can be accessed/borrowed from the
primary user(s) (license assignee) of spectrumX when/where the
primary user(s) are not using the radio resource and then spectrumX
can be released/returned to the primary user(s) when/where the
radio resource is needed back by the primary user(s). A new
signaling paradigm is employed to notify all spectrumX secondary
active radio users in a specific region, referred to herein as
location of spectrumX use, the access intention of a spectrum
primary user. The message signaled, herein referred to as signal-0,
may be technology and protocol agnostic in order to be detected by
a potential heterogeneous distribution of active users in the
location of spectrumX use.
[0018] In an embodiment, the mechanism to drive this type of
orchestration allows primary users seeking admission to their own
spectrumX to transmit a technology/protocol agnostic message
signal-0 at the beginning of their session. If a secondary user is
using spectrumX in the location of spectrumX use detects a signal-0
from a higher access priority entity then it will abandon spectrumX
immediately.
[0019] FIG. 1 illustrates a high level block diagram of a system
that utilizes an embodiment of the spectrum admission control
mechanism. The system provides two levels of priority access to
spectrumX. FIG. 1 shows a primary user 101 and three different
groups of secondary users 103, 105, and 107. In the embodiment of
FIG. 1, the primary user is a radar system. Secondary users 103,
which can be, e.g., wireless local area network access points,
utilize spectrum B4 during time period 106. Secondary user group
105, for example a wireless operator using Universal Mobile
Telecommunications Service (UMTS), utilizes spectrum B4, B1, and B5
during time period 106. Secondary user group 107, for example a
wireless operator using Long Term Evolution (LTE) communications
and may include eNodeB 116 and small cells 114, utilizes spectrum
B2, B3, and B4 during time period 106.
[0020] At time 108, primary user 101 sends out a signal-0 message
to all spectrumX secondary users in the location of spectrumX use
about the primary user's intention to use spectrum-X. For example,
if the second user is an LTE wireless operator in group 107, the
signal-0 message may be propagated to the eNodeB in proximity to
the primary user platform location, using spectrumX. Similarly,
signal-0 may be propagated to the closest access point(s) of a
wireless local area network or a base station using other
technologies. While FIG. 1 shows signal-0 being transmitted
wirelessly, in other embodiments, as described further herein,
signal-0 may be transmitted over wireline or over both wireline and
wirelessly to reach all secondary users. In the case of signal-0
being transmitted wirelessly, the power of the B4 spectrum rises
(as shown at 108 in FIG. 1) to values above normal traffic to
ensure the secondary user receive the signal-0 message correctly.
Signal-0 carries elemental information regarding a primary users
access modalities such as the planned
duration-of-spectrumX-utilization and location of spectrumX use,
e.g, latitude and longitude. Upon reception and decoding of
signal-0 all active secondary radio users will free up spectrumX in
the location of spectrumX use for the duration of spectrum
utilization communicated in signal-0 information contents.
[0021] During the duration-of-spectrumX utilization (time period
110) by the primary user of spectrumX the location of spectrumX use
112 is shown to encompass the geographic regions of secondary users
103, 105, and 107. In the embodiment illustrated in FIG. 1,
spectrumX is the spectrum B4. During the time period 110 the
secondary users do not use spectrum B4. Secondary user group 103,
which previously had been using spectrum B4, uses no radio spectrum
during time period 110. Secondary user group 105 uses spectrum B1
and B5 during time period 110. Secondary user group 107 uses
spectrum B2 and B3 during time period 110.
[0022] At time 115, the duration of spectrumX use ends. The
secondary users 103, 105, and 107 resume using spectrum B4 during
time period 117. The spectrum use by the secondary users during
time period 117 is similar to the use during time period 106. Power
levels of the B4 spectrum drop back to the normal traffic level
120.
[0023] Initial access to spectrum resources spectrumX by secondary
users may be regulated by a variety of mechanisms. For example,
secondary users may detect if there is any energy in spectrumX and
then proceed to use spectrumX if use by a primary user is not
detected. That technique is commonly known as Listen Before Talk
(LBT). Thus, a new secondary user 119 in secondary users 103 during
time period 117 may detect by measurement if the primary user is
using spectrumX via LBT, and if not, then begin use of spectrumX.
However, when the primary user 101 issues the next signal-0 message
at 120, all secondary users in the region of spectrum use,
including secondary user 119, relinquish use of the spectrum B4 to
the primary user 101 for the duration specified in the signal-0
message 120.
[0024] In embodiments described herein the utilization of signal-0
is employed by primary users seeking access to their spectrum
resource when there are only primary and secondary users. In other
embodiments, additional access priority gradations to spectrumX may
exist. For example, as shown in FIG. 2A, three separate categories
of access priority may exist, primary user(s) 201, secondary
user(s) 203, and tertiary user(s) 205.
[0025] FIG. 2B shows an example geographic distribution of use of
spectrumX where primary user 201 uses spectrumX in region 202,
secondary user 203 uses spectrumX in region 204, and tertiary user
205 uses spectrumX in region 206. Primary users have the highest
priority access rights, secondary users have the second highest
priority access rights and tertiary users have the lowest access
priority rights. Signal-0 207 sent by primary user 201 causes the
secondary users 203 and tertiary users 205 to relinquish use of
spectrum in regions 205 and 206. A similar signaling (signal-1) 209
may be employed by the secondary user(s) 203 to gain access to
spectrumX and force tertiary users 205 off of the spectrum. Thus, a
user with secondary access priority to the spectrum, can send a
signal-1 to those users with tertiary access authority forcing the
tertiary users off of spectrumX. Signal-1 carries elemental
information regarding the intermediate users access modalities such
as the planned duration-of-spectrumX-utilization and location of
spectrumX use. Upon reception and decoding of signal-1 all active
radio users with tertiary access authority free up spectrumX in the
location of spectrumX use and for the
duration-of-spectrumX-utilization communicated in signal-1
information contents.
[0026] In the spectrum sharing scheme, multiple technologies could
be deployed in the same spectrum block named spectrumX. For
example, the technologies may include broadcast, satellite
communications, radar, avionic, cellular, and any of a wide variety
of technologies that utilize spectrum. Consequently a technology
agnostic signaling may be employed to communicate the intention to
access spectrumX along with the rights and the planned modality to
do so to all active entities in location of spectrumX use. As
opposed to the conventional admission requests where a device is
admitted to use a series of resources (e.g. spectrum, radio
hardware, radio software, transport, etc) in this case the request
solely involves the spectrum block resource occupation in a defined
region and specific time. Thus, the signal-0 message is as
technology independent as possible specifying the spectrum
resource, the geographic region of intended use of that resource,
and the time duration of that use.
[0027] Machine learning type of functionalities may be employed to
learn primary users spectrumX utilization patterns in order to
reduce signaling to a minimum, where for example, the primary users
are a rotational radar, time defined broadcasted news, forecast
radio, or highway traffic broadcast.
[0028] Referring to FIGS. 3A, 3B, and 3C, various approaches to
propagating signal-0 to secondary users are shown. In FIG. 3A
signal-0 is wirelessly transmitted from primary user node 301
(showed as a rotational radar) to the closest secondary users nodes
in geographic region 303 (showed as macro radio base station and/or
small cells). That may allow less power to be used in transmitting
signal-0 as compared to the approach illustrated in FIG. 1. The
signal-0 message may then be propagated wirelessly, to additional
nodes 306 and 309 etc. The propagation through the location of
spectrumX-use via wireless transmission continues until all
secondary user nodes within the cluster in location of spectrumX
have received the signal-0 message. The time to propagate the
signal-0 message to all secondary users is constrained by the start
time of the primary user of spectrumX after the initial signal-0
message is sent by the primary user.
[0029] FIG. 3B illustrates an embodiment in which signal-0 is
transmitted from primary user node 301 (shown as a rotational
radar) to the closest secondary user nodes in geographic region 303
(showed as enodeB or small cells) via wireline 311. Signal-0 is
then propagated via wireline to the remaining secondary users nodes
in the location of spectrumX-use. The signal-0 transmission,
whether wireline of wireless, may be as simple as a sufficient
number of bytes of information specifying spectrum, geographic
location, and duration of use. Thus, the protocol may be very
simple so as to be agnostic to the particular technology being
utilized. As long as the bytes can be sent and received, the
signal-0 message can be utilized.
[0030] FIG. 3C illustrates an embodiment in which a hybrid approach
is used. Signal-0 is transmitted from primary user node 301 (shown
as a rotational radar) to the closest secondary user nodes in
region 303 via wireless transmission. Signal-0 is then propagated
via wireline to the remaining secondary users nodes in the location
of spectrumX-use. In other embodiments, additional hybrid
approaches where any portion of the signal-0 propagation to
secondary users nodes by the primary user nodes or other secondary
users nodes may be via wireline or wireless. Of course secondary
users should be aware of their geographic location in order to
properly respond to the signal-0 message.
[0031] A viable method to propagate signal-0 information throughout
the location of SpectrumX for an LTE network cluster is to allow
the proximity base station (e.g. the one illustrated in region 303
in FIG. 3A), once it receives the signal-0 content from the primary
user, to propagate signal-0 (and/or signal-1) including spectrum,
region and duration to its neighbors over the X2 interface, such
that if the X2 neighbor is within the location of spectrumX use,
the X2 neighbor will re-transmit signal-0 and signal-1 over X2 to
neighbors. The X2 interface provides communications between
eNodeBs. However, if the X2 neighbor is beyond the location of
spectrumX use the X2 neighbor takes no action, thus limiting the
reach (and associated signaling overhead) of the signal-0 and
signal-1 transmission(s).
[0032] FIG. 4 illustrates a high level flow diagram of a secondary
user node deactivating and resuming use of spectrumX. In 401 the
secondary user node is assumed to be using spectrumX and is waiting
for a signal-0 message. The secondary user node continues to wait
for the signal-0 message in 401. When the signal-0 message is
received, the secondary user node deactivates spectrum in 403. The
secondary user node maintains spectrumX deactivated while waiting
in 405 for a time period specified by the duration of use field in
the signal-0 message to expire. When the time period has expired,
indicating that the primary user node is no longer using spectrum,
the secondary user node resumes using spectrumX (if desired) in
407.
[0033] FIG. 5 illustrates an exemplary base station, such as an
eNodeB, small cell base station, or an access point for local area
network. To provide further context for various aspects of the
subject specification, FIG. 5 provides a high level block diagram
of an example embodiment 500 of a base station that may be used to
implement the spectrum access approach described herein. For
simplicity, FIG. 5 will be described simply as a base station with
the understanding that the high level blocks implemented may be
modified according to the needs of the specific radio technology
used by the secondary user. In one aspect, the base station 500 can
receive and transmit signal(s) (e.g., data traffic and control
signals) to and from user equipment, through a set of antennas
509.sub.1-509.sub.N, for example, utilizing some or all of the
spectrum B1-B5 shown in FIG. 1. Antennas 509.sub.1-509.sub.N form
part of communication platform 525, which includes electronic
components and associated circuitry for processing received
signal(s) (data and control) and for processing signals (data and
control) to be transmitted. Communication platform 525 can include
a transmitter/receiver (e.g., a transceiver) 566 that can convert
signal(s) from analog format to digital format upon reception, and
from digital format to analog format for transmission. In addition,
transceiver 566 can divide a single data stream into multiple,
parallel data streams, or perform the reciprocal operation. Coupled
to transceiver 566 is a multiplexer/demultiplexer 567 that
facilitates manipulation of signals in the time and/or frequency
domain. Multiplexer/demultiplexer 567 can multiplex information
(data/traffic and control/signaling) according to various
multiplexing schemes such as time division multiplexing (TDM),
frequency division multiplexing (FDM), orthogonal frequency
division multiplexing (OFDM), filtered OFDM, etc. In addition,
multiplexer/demultiplexer component 567 can scramble and spread
information (e.g., codes) according to substantially any code known
in the art. A modulator/demodulator 568 is also a part of
communication platform 525, and can modulate information according
to multiple modulation techniques, e.g., M-ary quadrature amplitude
modulation (QAM), with M a positive integer), phase-shift keying
(PSK), and the like. The communication platform 525 may include
appropriate circuitry to decode the signal-0 message. For example,
the signal-0 message may be in a format that varies according to
whether the primary user is a TV broadcast or a radar and the
communication platform 525 may be adapted to accommodate one or
more signal-0 message formats.
[0034] Base station 500 also includes one or more processors 545
configured to confer functionality, at least partially, to
substantially any electronic component in the base station 500, in
accordance with aspects of the subject disclosure. In particular,
processor 545 can facilitate implementing configuration
instructions, which can include storing data in memory 555. In
addition, processor 545 can facilitate processing data (e.g.,
symbols, bits, or chips, etc.) for multiplexing/demultiplexing,
such as effecting direct and inverse fast Fourier transforms,
selection of modulation rates, selection of data packet formats,
inter-packet times, etc. Moreover, processor 545 can manipulate
antennas 509.sub.1-509.sub.N to facilitate beamforming or selective
radiation pattern formation, which can benefit specific locations
covered by the base station 500; and exploit substantially any
other advantages associated with smart-antenna technology. Thus,
the one or more processors 545 may include digital signal
processing capability to effectuate necessary functions associated
with reception and transmission of information via antennas
509.sub.1 to 509.sub.N. Thus, the one or more processors 545 may
implement a significant portion of the processing in communication
platform 525.
[0035] Memory 555 can store data structures, code instructions, and
specify capabilities, code sequences for scrambling, spreading and
pilot transmission, floor plan configuration, access point
deployment and frequency plans, and so on. In one example, computer
instructions to help implement the spectrum access scheme described
in relation to FIGS. 1-3C and FIG. 4 may be stored in memory
555.
[0036] Processor 545 can be coupled to the memory 555 in order to
store and retrieve information necessary to operate and/or confer
functionality to communication platform 525, network interface 535
(e.g., that coupled the access point to core network devices such
as but not limited to a network controller), and other operational
components (e.g., multimode chipset(s), power supply source; not
shown) that support the access point 500. The access point 500 can
further include an interface 565 for wired communication with a
primary user and/or other secondary users. Wired communications
with primary and/or secondary users may instead utilize network
interface 535. The access point may also include component 575 to
activate/deactivate spectrumX in response to the signal-0 message.
Thus, component 575 may cause deactivation of spectrumX in response
to the signal-0 command and reactivation of spectrumX at the end of
the duration specified in the signal-0 message. In addition, it is
to be noted that the various aspects disclosed in the subject
specification can also be implemented through (i) program modules
stored in a computer-readable storage medium or memory (e.g.,
memory 555) and executed by a processor (e.g., processor 545), or
(ii) other combination(s) of hardware and software, or hardware and
firmware.
[0037] In the subject specification, terms such as "data store,"
data storage," "database," "cache," and substantially any other
information storage component relevant to operation and
functionality of a component, refer to any form of memory that can
store information and be read by computers or processors. Memory
may be volatile memory or nonvolatile memory, or both. Nonvolatile
memory can include read only memory (ROM), programmable ROM (PROM),
electrically programmable ROM (EPROM), electrically erasable ROM
(EEPROM), or flash memory. In addition non-volatile memory can
include magnetic and optical memory. Volatile memory can include
random access memory (RAM), available in many forms such as
synchronous RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM
(SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM
(ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM).
Additionally, the disclosed memory components of systems or methods
herein are intended to comprise, without being limited to
comprising, these and any other suitable types of memory.
[0038] Thus, aspects of sharing spectrum between primary and
secondary users with potentially very different technologies have
been described. The description set forth herein is illustrative,
and is not intended to limit the scope of the following claims.
Variations and modifications of the embodiments disclosed herein
may be made based on the description set forth herein, without
departing from the scope of the following claims.
* * * * *